In a multicarrier or carrier aggregation technology, a terminal may send data in a same subframe to a base station by using multiple carriers, where the multiple carriers may have different frequencies. It is well known that delays in a process of sending data to a base station over carriers of different frequencies are different, and to ensure that data carried over multiple carriers in a same subframe can arrive at the base station at the same time, when the terminal uses multiple carriers to send the data, the terminal needs to use, according to different frequencies of the carriers, different transmit timing values to send the data to the base station. In a traditional solution, it may be learned that the terminal has a limitation on a maximum value of uplink transmit power. In other words, when the terminal uses multiple carriers to send data to the base station, the terminal allocates the uplink transmit power by subframe. That is, in a same subframe, if the terminal uses the multiple carriers to send the data to the base station, a sum of transmit power of the multiple carriers is not allowed to exceed the maximum value of the uplink transmit power of the terminal. In the foregoing case, different transmit timing values are used when data is sent over carriers of different frequencies; therefore, the carriers of different frequencies have an overlapped area in different subframes, and a sum of transmit power of these carriers in the overlapped area may exceed the maximum value of the uplink transmit power of the terminal. In this way, transmit power of the terminal may exceed a limit, thereby affecting transmission of data.
When a time span of the overlapped area is relatively short, a case in which the sum of the transmit power of the carriers in the overlapped area exceeds the maximum value of the uplink transmit power of the terminal may be resolved in the prior by means of power allocation or a rollback operation. However, when the time span of the overlapped area is relatively long, a problem that the sum of the transmit power of the carriers in the overlapped area exceeds the maximum value of the uplink transmit power of the terminal cannot be resolved in the prior art by means of power allocation or a rollback operation. In this case, a probability that power of the terminal exceeds a limit is very high. Therefore, how to reduce the probability that the power of the terminal exceeds a limit has become an important issue researched by a person skilled in the art.